DNO discovers oil in Othello prospect offshore Norway
DNO ASA discovered oil in the Othello prospect in production license (PL) 1086 in the southern North Sea. Preliminary estimates indicate the size of the discovery is about 4-9 million std cu m of oil equivalent (25-57 MMboe).
Wildcat 2/6-7 S and appraisal 2/6-7 A were drilled in 56 m of water by the Noble Invincible jack-up rig. These are the two first exploration wells in the license.
Wildcat well 2/6-7 S was drilled to a vertical depth of 3,642 m subsea. It was terminated in the Smith Bank formation in the Upper Triassic. The primary exploration target was to prove petroleum in Upper Jurassic reservoir rocks in the Ula formation (Falstaff prospect). This secondary exploration target was to prove petroleum in Palaeocene reservoir rocks in the Borr Member in the Våle formation (Othello prospect).
Appraisal well 2/6-7 A was drilled to 2,987 m TVD and 3,386 m MD subsea. It was terminated in the Ekofisk formation in the Lower Palaeocene. The objective of appraisal well 2/6-7 A was to confirm the size of the discovery in the Borr member.
Wildcat well 2/6-7 S encountered an oil column in the Borr Member, spanning two sandstone layers totaling 16 m with moderate to good reservoir quality. The oil-water contact was not encountered. This is the first moveable oil encountered in the Borr unit of the Våle formation in the Norwegian sector, and it is considered a play opener.
No reservoir was present in the primary exploration Falstaff target in the Ula formation.
Appraisal well 2/6-7 A encountered a 12-m oil column in the Borr Member, 8 m of which were in a sandstone reservoir. The Borr Member had a total thickness of 39 m, 26 m of which was net sand of moderate-to-good reservoir quality. A possible oil-water contact was encountered at 2,929 m below sea level.
The wells were not formation-tested, but extensive data acquisition and sampling have been carried out.
DNO is considering tying the discovery back to existing infrastructure, with the ConocoPhillips Ekofisk hub about 40 km to the west and the Valhall hub operated by Aker BP ASA about 55 km to the southwest.
The wells have been permanently plugged and abandoned. Noble Invincible will move to drill a production well on the nearby Tambar East oilfield in which DNO holds a 37.8% interest.
DNO is the operator of the PL 1086 joint venture (50%) with partners Petoro AS (20%), Aker BP (20%), and Source Energy (10%).
Alex Procyk | Upstream Editor
Alex Procyk is Upstream Editor at Oil & Gas Journal. He has also served as a principal technical professional at Halliburton and as a completion engineer at ConocoPhillips. He holds a BS in chemistry (1987) from Kent State University and a PhD in chemistry (1992) from Carnegie Mellon University. He is a member of the Society of Petroleum Engineers (SPE).